In the human vision system, the retina is a light-sensitive layer of tissue, covering the inner surface of the eye. An image of a viewed scene is created on the retina (i.e., through the eye lens). Light impinging on the retina triggers nerve impulses sent to visual areas of the brain.
Retinal surgeries, as known in the art, involve the placement of a macular lens on the eye and insertion of an illumination optical fiber into the eye ball for illuminating the retina. For example, one surgeon (or a fixture) holds the macular lens on the top surface of the eye, the cornea, while another holds the illumination fiber and other surgical tools. Thus, the illumination fibers are aimed manually. Additionally, the distribution angle of the illuminating fiber beam (i.e., or the illuminated spot generated thereby) is relatively narrow. Therefore, the surgeon holding the fiber has to constantly redirect the illumination fiber for illuminating the area of interest investigated under a microscope.
Reference is now made to US Patent Application Publication No. 2012/0050683 to Yates, entitled “Self-Illuminated Handheld Lens for Retinal Examination and Photography and Related Method thereof”. This publication is directed to a handheld fundus lens with integrated lighting fibers. The hand held fundus lens of this publication provides illumination to the patient's retina from a point source of light through fiber optics strands. The light source is positioned outside the lens and is directly coupled to the fiber optic strands. A light channel is ground into the contact lens, and the fiber optic strands are inserted into this light channel. The fiber optic strands are formed into an illumination ring abutting the contact lens.
WO 95/14254 to Donald A. Volk entitled “Indirect ophthalmoscopy lens system and adapter lenses” is directed to an ophthalmoscopic or gonioscopic lens system. The indirect ophthalmoscopy lens comprises a hand-held, pre-set or fixed system having at least two lens elements each having first and second surfaces. The at least two lens elements are positioned adjacent one another in a housing, such that the refractive properties of each are combined to converge light from an illumination light source to the entrance pupil of the patient's eye to illuminate the fundus thereof and form a fundus image to be viewed. The adapter lens systems of this invention are designed for use with an associated ophthalmoscopic lens, enabling selective modification of the optical characteristics of the ophthalmoscopic lens system in a predetermined manner.
US 2009/0185135 to Donald A. Volk entitled “Real image forming eye examination lens utilizing two reflective surfaces providing upright image” describes a diagnostic and therapeutic contact lens for use with biomicroscopes for the examination and treatment of structures of the eye. The lens comprises a contacting surface adapted for placement on the cornea of an eye, two reflecting surfaces, and a refracting surface. A light ray emanating from the structure of the eye enters the lens and contributes to the formation of a correctly oriented real image. The light ray is reflected in an ordered sequence of reflections, first as a negative reflection in a posterior direction from an anterior reflecting surface and next as a positive reflection in an anterior direction from a posterior reflecting surface. The light ray contributes to forming the image of the structure of the eye either anterior to the lens or within the lens and proceeds along a pathway to the objective lens of the biomicroscope used for stereoscopic viewing and image scanning.